N54 Cooling - Temp Control Logic and what are your temps during extended track use?

[KClemente]

Anyone had experience with aftermarket electric water pumps (from other platforms perhaps)? I'm considering ditching the stock pump as they are getting pricey locally to me, and I've had issues with cracked housings etc. Meziere, Davies Craig and others appear to have options that might be more durable. Compact size with sufficient flow rate is probably the criteria given our tightly packed engine bays. Running syvecs, not worried about control. Some of them have their own control units in any case.

Have you considered casting an aluminum cover for one of your cracked pumps? I saw a video a while back of someone using their homemade forge and casting a new cover. A little belt sanding and some rtv sealant and I think it'll be a viable option. The stock pump is very capable, just a shame they have the reliability of the N63 valve stem seals..

 

[Bnks334]

Did a little carving on the bumper cover to get more direct airflow to the intercooler. Inlets on either side are for brake cooling ducts.

What splitter is that?

 

[MDORPHN]

What splitter is that?

The cf lip is made by Slek. When I'm on track, I attach a splitter that extends about 6" forward that I fabricate from dibond.

Neil

 

[Bnks334]

The cf lip is made by Slek. When I'm on track, I attach a splitter that extends about 6" forward that I fabricate from dibond.

Neil

Does the splitter stick out past the plane of the most outward portion of the bump?

 

[MDORPHN]

Does the splitter stick out past the plane of the most outward portion of the bump?

Let's take it offline if you have any further questions.

 

[rac]

Have you considered casting an aluminum cover for one of your cracked pumps? I saw a video a while back of someone using their homemade forge and casting a new cover. A little belt sanding and some rtv sealant and I think it'll be a viable option. The stock pump is very capable, just a shame they have the reliability of the N63 valve stem seals..

Link to video? Most likely outside of my capability.

 

[berns]

Here's an example of a single vs stock twins when it comes to track cooling. Identical cooling setups here, same track, similar ambient temps and fueling.

First graph: CES Motorsport ST kit with Garrett GTX3076 @ 16psi, CSF intercooler, CSF radiator, twin Setrab 19-row oil coolers, Redline 10-40, E30

Second graph: Stock twins, 15psi, identical cooling as above, E30

 

[gmx]

When was the last time you dumped coolant on the last graph? I don't remember if you exchanged it with the CSF.
For example... my coolant temps dropped 15C just by dumping the 7 year old stuff (not the block) in there and diluting it more. With any single as you know, you dump the fluids and refill fresh.
Not denying how much a single would be, moreso wondering how skewed this data could be.

 

[berns]

When was the last time you dumped coolant on the last graph? I don't remember if you exchanged it with the CSF.
For example... my coolant temps dropped 15C just by dumping the 7 year old stuff (not the block) in there and diluting it more. With any single as you know, you dump the fluids and refill fresh.
Not denying how much a single would be, moreso wondering how skewed this data could be.

Coolant in the system was distilled water & factory coolant with stock turbos. It was fresh, as I changed it when I got the car 2 years prior.
It's currently 100% distilled water. Regardless, this system works as whole... It's pretty safe to say and blatantly obvious that the entire system is cooler and happier, and it makes a lot of sense.

 

[Jeffman]

Very informative, @berns. So do we read your results to say that the much lower IATs with the GTX (arising from better compressor efficiency over the stock twins) results in the much lower coolant and oil temps?

 

[Bnks334]

Very informative, @berns. So do we read your results to say that the much lower IATs with the GTX (arising from better compressor efficiency over the stock twins) results in the much lower coolant and oil temps?

Probably has much more to do with the stock twins pumping coolant and oil through the turbos lol.

 

[berns]

Probably has much more to do with the stock twins pumping coolant and oil through the turbos lol.

It's all relative. Two tiny turbos blowing hot air, spinning well beyond where they should, heating up oil and coolant, choking the motor, pumping more hot air into the system, raising temps all around. It's just not efficient.

 

[Jeffman]

That makes sense. I hadn’t realized that the top mount GTX doesn’t require coolant and/or oil flowing though it. Is this the case with most top mounts?

 

[berns]

That makes sense. I hadn’t realized that the top mount GTX doesn’t require coolant and/or oil flowing though it. Is this the case with most top mounts?

No, you're way off here. The Garrett is both oil and water cooled. It's also not a top mount kit from CES, however that part is irrelevant here. Some turbos are just oil cooled. Whether that has an impact on the thermal characteristics of the motor and fluids, I'm not sure. The only point I'm trying to make here is an obvious one. Just nice to have some clear data. I have yet to see temperature readings from twins that look this good, but happy to be shown otherwise.

 

[Jeffman]

Agreed. Good to see the data. Now why such a big difference in oil and coolant temps? I’d like to understand the key design and operational differences between the GTX and the stock twins to result in such a huge difference in oil and coolant temps.

 

[Asbjorn]

Here's an example of a single vs stock twins when it comes to track cooling. Identical cooling setups here, same track, similar ambient temps and fueling.

First graph: CES Motorsport ST kit with Garrett GTX3076 @ 16psi, CSF intercooler, CSF radiator, twin Setrab 19-row oil coolers, Redline 10-40, E30
View attachment 35258

Second graph: Stock twins, 15psi, identical cooling as above, E30
View attachment 35259

Thanks for sharing. This is a very interesting topic indeed.

We really need to know the exact differences in ambient conditions (temp + humidity). It has a huge influence on cooling performance in my experience.

 

[gmx]

That makes sense. I hadn’t realized that the top mount GTX doesn’t require coolant and/or oil flowing though it. Is this the case with most top mounts?

I can't find how to search within a thread on this forum, but we've already alluded that a single is more efficient than twins.
It's one turbo and one CHRA to cool running well within it's compressor map (16psi). And this data establishes that.

It reaffirms for me, keep it simple and keep the turbos efficient and in the comp map.
Time and time again, street / strip tunes on these stock frames/aftermarket twins with shaft speeds through the roof just don't cut it on track.

 

[Bnks334]

I imagine the single turbo is still getting plenty hot. Run the stocks twins on stock tune and you'll have just as much heat issues. Two turbos to be cooled vs one.

But like Asbjorn said, without ambient temps the data is useless. could be a 70f day vs a 90f day.

 

[Asbjorn]

Agree with @Bnks334

Even stock power n54, especially dct versions, are notorious for hitting limp mode when it gets hot.

On the other hand, stock power s55 engines are used for competitive endurance racing.

Both twin turbo engines running boost within efficient ranges.

Main difference is that one has a radiator that is almost 50% smaller than the other (if you deduct the rows used for dct cooling, and forget about the ppk equipped cars).

Almost half the size!

And it's a similar story with the engine oil cooler.

If it was really possible to run a tiny radiator, which overheats already at 300hp running twins, on a 500hp race car, just by going single, then I think everyone would be doing that, no?

It seems that all serious track cars, no matter n/a, supercharged, single or twin all run radiators that are much larger in terms of area-to-horsepower than the stock n54. That is unless they run on pure methanol, rockets or batteries haha.

 

[GrazieVale]

First of all thanks for the knowledge acquired reading by reading the entire thread.
Started with a question that's not been touched (imagine that) which is in a e92 m sport I'm thinking of upgrading the oil cooler, the main radiator with a csf one and on the passanger side I'm in the fence between a trans cooler or an auxiliary radiator (both as big as possible). It crossed my mind to just do both but might save that if v1 doesn't work as intended.
Frequent mountain and not and track use of course.

Thanks again guys.